アルゴリズムと数学 077

https://atcoder.jp/contests/math-and-algorithm/tasks/math_and_algorithm_bj

xとyを分けるだけですね。

// Distance Sum
#![allow(non_snake_case)]


//////////////////// library ////////////////////

fn read<T: std::str::FromStr>() -> T {
    let mut line = String::new();
    std::io::stdin().read_line(&mut line).ok();
    line.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>().split_whitespace()
            .map(|e| e.parse().ok().unwrap()).collect()
}


//////////////////// process ////////////////////

type Point = (i64, i64);

fn read_point() -> Point {
    let v = read_vec();
    (v[0], v[1])
}

fn read_input() -> Vec<Point> {
    let N: usize = read();
    let points: Vec<Point> = (0..N).map(|_| read_point()).collect();
    points
}

fn g(mut A: Vec<i64>) -> i64 {
    A.sort();
    let N = A.len();
    let mut s: i64 = 0;
    for i in 0..N {
        s += (1 - (N as i64) + 2 * (i as i64)) * A[i]
    }
    s
}

fn f(points: Vec<Point>) -> i64 {
    let xs: Vec<i64> = points.iter().map(|&(x, _)| x).collect();
    let ys: Vec<i64> = points.iter().map(|&(_, y)| y).collect();
    g(xs) + g(ys)
}

fn main() {
    let points = read_input();
    println!("{}", f(points))
}